https://hydro.ac/d/luogu/record/6590eb14e0f750084483811c

#include<iostream>
#include<cmath>
#include<cstring>
#include<string>
#include<cstdio>
#include<algorithm>
#include<stack>
#include<queue>
#include<iomanip>
using namespace std;

int n,m,a[1002][1002],x,y,x2,y2;

int main(){
	cin >> n >> m;
	for(int i=1;i<=m;i++){
		scanf("%d %d %d %d",&x,&y,&x2,&y2);
		for(int j=x;j<=x2;j++){
			for(int k=y;k<=y2;k++){
				a[j][k]+=1;
			}
		}
	}
	for(int i=1;i<=n;i++){
		for(int j=1;j<=n;j++){
			printf("%d ",a[i][j]);
		}
		cout << '\n';
	}		
	return 0;
}

https://www.luogu.com.cn/record/141532614